1. Field of the Invention
This invention relates to an electric power tap permanently attached to an electric receptacle. More particularly, this invention relates to an electrical power tap or other electrical device permanently attached to a duplex electrical wall receptacle and means for permanently attaching same.
2. Backqround of the Disclosure
Various electric taps are employed both in the home and in industry which are plugged into or attached in one way or another to a duplex electric wall receptacle. Such devices include, for example, (i) multiple outlet power taps which plug into duplex electric wall receptacles to convert the duplex receptacle to three or more line power taps and (ii) power line voltage surge protection devices which contain circuitry designed to safeguard electronic appliances from power surges caused by normal power switching found in every home, as well as overloads and, in some cases, even lightning. Such power surge protection devices also often contain a plurality of power taps for providing line voltage to the electronic appliance or appliances. Such electronic appliances include computers, VCR's, microwave ovens, high fidelity stereo equipment, various telephonic equipment, etc.
The technique most often used at the present time for mounting such electrical devices to a wall receptacle involves the use of a single mounting screw which replaces the screw that holds the wall plate to the receptacle. Some devices involve removing and tap serves as a combination wall plate and tap in one device. Such devices must fully cover or enclose the area of a standard-sized wall plate utilized with a conventional, duplex receptacle. Thus, in mounting these devices or taps to the receptacle, they must be in contact with the wall which can limit the depth of the insertion of the tap's blades into the wall receptacle. Taps utilizing this method of mounting where the wall becomes the interference can have problems with respect to a reduced amount of contact area of the blades of the plug with the contacts within the receptacle. In some cases, this can prevent a sound electrical contact between the tap and the receptacle.
On the other hand, when the wall plate is not removed and discarded, it is often dislodged from its position by the process of inserting the tap into the receptacle before the single screw is inserted through the tap to secure both the tap and wall plate to the receptacle. The consumer must then contact and reposition the potentially live wall plate. Consequently, an electrical shock hazard may result if the wall plate is metal, by shorting the blades of the tap or becoming electrically alive due to contact with one of the blade members in the dislodged position. This can also result in breakage of a glass or ceramic wall plate.
Another method of permanent mounting currently in use involves a mounting tab which rests on the surface of the wall plate. In this case, a single screw is used to attach a plug adapter, such as those employed to convert a three-wire receptacle to a two-wire receptacle. A single screw attaches both the plug and the wall plate together to the receptacle. This is a compression fit which serves to retain both the plug and the wall plate securely to both the wall and the receptacle and is not practical with large taps.
Accordingly, there is still a need for a safer and more certain method for mounting taps to duplex wall receptacles so that the tap rests on the surface of the receptacle and is not stopped or interfered with by the wall or the structure of the building. In this way, blade penetration or depth in the receptacle is deterministic and will always yield a safe, reliable electrical connection.